CN113427391B

CN113427391B - Automatic water mill equipment

Info

Publication number: CN113427391B
Application number: CN202110036364.5A
Authority: CN
Inventors: 林隆治
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2020-03-05
Filing date: 2021-01-12
Publication date: 2023-05-23
Anticipated expiration: 2041-01-12
Also published as: US20210276148A1; JP7338515B2; CN113427391A; US11701752B2; JP2021137917A

Abstract

In an automatic water mill apparatus including a disk and a cushion pad, a disk center hole is formed at a center portion of the disk, and a cushion center hole is formed at a center portion of the cushion pad. The water that has been supplied to the introduction space inside the skirt portion is stirred as the eccentric head eccentrically rotates, and thereby is pushed out toward the application surface via the disk center hole and the pad center hole with an enhanced pressure. Therefore, the polishing dust caused by the automatic water mill can be washed away toward the outer peripheral side by the water pushed toward the outer peripheral side, so that the possibility of clogging due to the polishing dust can be reduced, and high polishing efficiency can be maintained.

Description

Automatic water mill equipment

Technical Field

The invention relates to an automatic water mill device. In particular, the present invention relates to improvements to the water flow inside an automatic water mill unit.

Background

Currently, there is known an automatic water mill apparatus that performs automatic water milling on a coated surface of a vehicle body after a coating process is completed in an automobile production line, for example, as disclosed in japanese patent application laid-open No. 58-67377.

The automatic water mill apparatus includes an automatic water mill unit mounted on an automatic water mill robot (e.g., an articulated robot). The automatic water mill unit includes a grinding slider such as a grinding brush or grinding paper. In the automatic water-milling process, the grinding slide body is pressed against the coated surface, and the automatic water-milling robot is operated to move the grinding slide body along the coated surface in a state in which water flows between the grinding slide body and the coated surface to grind the coated surface.

Disclosure of Invention

In an automatic water mill apparatus, grinding dust such as paint dust may be retained due to grinding of the coated surface. For example, if the grinding dust stagnates around the grinding slide body, clogging due to the grinding dust may occur, and then the apparatus becomes unable to grind the coated surface effectively or it is difficult to maintain high grinding efficiency.

The present invention has been devised in view of the problem, and an object of the present invention is to provide an automatic water mill apparatus which can reduce the possibility of the retention of grinding dust.

The solution adopted by the present invention in order to achieve the above object is premised on an automatic water mill apparatus that performs the following automatic water mill: in the automatic water mill, the grinding slide body is pressed against the coated surface of the coated object that has been coated, and the grinding slide body moves as water flows between the grinding slide body and the coated surface to grind the coated surface. The automatic water mill apparatus includes: a housing forming a water introduction space; a water supply pipe supplying water to the introduction space; a disk positioned closer to the coating surface than the lead-in space in a state where the automatic water mill is performed; a cushion pad integrally moved with the disk, and on which the grinding slider is mounted; a disk center hole formed at a center portion of the disk; a pad center hole formed at a center portion of the cushion pad and communicating with the disk center hole; and an ejector that ejects water, which has been supplied to the introduction space through the water supply pipe, toward the application surface via the disc center hole and the pad center hole.

According to these specific requirements, during the realization of the automatic water mill for grinding the coated surface of the coated object, water that has been supplied to the introduction space inside the housing through the water supply pipe is pushed out toward the coated surface by the push-out device via the disk center hole of the disk and the pad center hole of the cushion pad. Therefore, in a state where water flows between the polishing slider and the coated surface, the polishing slider is pressed against the coated surface and moved to polish the coated surface. Since water is pushed out toward the coated surface via the disk center hole and the pad center hole, water is pushed out toward the outer peripheral side from the center portion of the polishing slider between the polishing slider and the coated surface while performing the automatic water polishing. Therefore, the polishing dust caused by the automatic water mill is washed away toward the outer peripheral side by the water pushed toward the outer peripheral side, so that the polishing dust does not remain around the polishing slider. Therefore, the possibility of clogging due to grinding dust can be reduced, and high grinding efficiency can be maintained.

The push-out device may have a stirring head which is provided inside the housing and which stirs the water located in the introduction space; and the disk may have a disk hole formed at a position relative to an outer peripheral side of the disk center hole, and the disk hole communicates with the introduction space, and a communication passage that communicates between the disk hole and the disk center hole.

In this configuration, the water in the introduction space inside the housing is stirred by the stirring head, and thereby pushed into the disk hole of the disk with an enhanced pressure, and then pushed out toward the application surface via the communication passage, the disk center hole, and the pad center hole. Therefore, water can be pushed out toward the coated surface with high pressure, so that the abrasive dust can be efficiently washed away toward the outer peripheral side, and thereby the possibility of clogging due to the abrasive dust is reliably reduced.

The automatic water mill apparatus may include a rotation power source for rotating the stirring head, and a center position of the stirring head may be deviated from a rotation center of a driving shaft of the rotation power source.

In this configuration, the eccentric rotation of the stirring head allows the rotational force of the drive shaft of the rotary power source to be easily converted into the pushing-out force for pushing out the water toward the coating surface, so that an effective water pushing-out operation can be achieved.

The position of the outer edge of the stirring head on the deviated side may be on the inner peripheral side with respect to the outer peripheral end of the disk hole.

In this configuration, a situation in which the eccentric head temporarily covers the entire disc hole while rotating (eccentrically) does not occur. In other words, at least a portion of the disc hole is always in communication with the introduction space. Therefore, the water passage through which the water that has been supplied to the introduction space is pushed out toward the coated surface can be always ensured, so that the water can be stably pushed out toward the coated surface, and an effect of reducing the possibility of clogging can be stably produced.

The disc may be supported by the stirring head so as to be rotatable relative to the stirring head. A sealing member made of an elastic material may be provided, one end edge of which is supported by the housing while the other end edge contacts a surface of the disk facing the introduction space, and which seals a gap between the housing and the disk.

In this configuration, when the water pressure introduced into the space increases, the sealing member is elastically deformed to leave a gap between the sealing member and the disk, and water flows through the gap. Thus, a high water pressure in the introduction space can be maintained, which can help to enhance the pressure of the water pushed out of the pad center hole toward the application face. Further, in this state, a water film (flowing water) exists between the sealing member and the disk. Therefore, even when the disk and the seal member move relative to each other as the disk rotates, the sliding resistance does not increase, so that relative movement can be allowed with little frictional loss.

The inner diameter of the disc center hole may be set smaller than the inner diameter of the pad center hole.

In this configuration, when water is pushed out from the relatively small-diameter disc center hole toward the relatively large-diameter pad center hole, the water is subjected to a large centrifugal force in the pad center hole, which can enhance the pressure of the water pushed out from the pad center hole toward the coated surface. Therefore, the abrasive dust can be efficiently washed away toward the outer peripheral side, thereby reliably reducing the possibility of clogging due to the abrasive dust.

The center position of the disk may be offset from the rotation center of the drive shaft of the rotary power source, and the offset may be sized to be less than half the inner diameter of the disk center hole.

In this configuration, since the center position of the disk is deviated from the rotation center of the drive shaft of the rotary power source, the disk eccentrically rotates with respect to the drive shaft. In this case, even when the disk center hole moves as the disk eccentrically rotates, the water flow passage inside the disk center hole can maintain a region where the flow of water is not disturbed by the movement of the inner wall of the disk center hole, and water can stably flow in the region. Therefore, the water can be pushed out toward the coated surface while maintaining a high pressure. This also helps to wash away the abrasive dust effectively toward the outer peripheral side, thereby reliably reducing the possibility of clogging due to the abrasive dust.

In the present invention, an automatic water mill apparatus including a disk and a cushion pad has a disk center hole formed at a center portion of the disk and a cushion pad center hole formed at a center portion of the cushion pad, and water is supplied toward a coating surface through the disk center hole and the cushion pad center hole by an ejector. Therefore, the polishing dust caused by the automatic water mill can be washed away toward the outer peripheral side by the water pushed toward the outer peripheral side, so that the possibility of clogging due to the polishing dust can be reduced, and high polishing efficiency can be maintained.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals denote like elements, and in which:

FIG. 1 is a schematic configuration diagram of an automatic water mill plant in an embodiment;

FIG. 2 is a schematic configuration diagram showing a first automatic water mill apparatus;

fig. 3 is a view showing an automatic watermill robot;

FIG. 4A is a longitudinal section of the automatic watermill unit;

fig. 4B is a schematic diagram showing a disc main body;

FIG. 5 is a schematic configuration diagram of a pad cleaning unit;

FIG. 6 is a schematic configuration view of a pad drainage unit;

fig. 7 is a schematic configuration diagram of the paper inspection unit;

FIG. 8 is a block diagram illustrating a control system of an automatic water mill apparatus;

FIG. 9 is a flow chart illustrating an automatic water milling operation by an automatic water milling apparatus;

fig. 10 is a sectional view showing the flow of water in the automatic water mill unit in a state where the automatic water mill is performed;

FIG. 11 is a side view of the vehicle body showing the path of movement of the automatic water mill unit in an automatic water mill operation;

FIG. 12 is a cross-sectional view showing the flow of water inside the disk and cushion;

fig. 13 is a longitudinal sectional view of the automatic water mill unit in modified example 1;

Fig. 14 is a side view of the automatic water mill unit in modified example 2; and

fig. 15 is a cross-sectional view of a floating joint structure of a rod end in modified example 2.

Detailed Description

Embodiments of the present invention will be described below based on the drawings. In this embodiment, a case where the present invention is applied to an automatic water mill apparatus that is provided on an automobile production line and performs automatic water milling on a coated surface of an automobile body will be described.

Schematic configuration of an automatic water mill plant

First, a schematic configuration of an automatic water mill shop on an automobile production line equipped with the automatic water mill apparatus will be described. Fig. 1 is a schematic configuration diagram of an automatic water mill shop 1 in this embodiment. The automatic water mill shop 1 is installed on an automobile production line and is located on the downstream side of a paint shop (not shown).

As shown in fig. 1, the automatic water mill shop 1 has the following configuration: in this configuration, four

automatic watermill apparatuses

21, 22, 23, and 24 are installed two by two on each side of the conveyor 11 that transfers the vehicle body V.

When the vehicle body V is transferred as indicated by arrow a in fig. 1 (when the vehicle body a is transferred from the left side toward the right side in fig. 1 on the conveyor 11), the automatic

water mill apparatus

21, 22 located on the downstream side in the transfer direction perform automatic water milling on the coated surfaces of the front gates LFD, RFD and front fenders LFF, RFF of the vehicle body V. Specifically, the automatic water mill apparatus 21 (hereinafter referred to as first automatic water mill apparatus 21) located on the left side (upper side in fig. 1) when seen from the transfer direction performs automatic water milling on the coated surfaces of the left front door LFD and the left front fender LFF of the vehicle body V. The automatic water mill apparatus 22 (hereinafter referred to as a second automatic water mill apparatus 22) located on the right side (lower side in fig. 1) when viewed from the transfer direction performs automatic water milling on the painting surfaces of the right front door RFD and the right front fender RFF of the vehicle body V.

On the other hand, the

automatic water mill

23, 24 located on the upstream side in the transfer direction perform automatic water milling on the coated surfaces of the rear doors LRD, RRD and rear fenders LRF, RRF of the vehicle body V. Specifically, an automatic water mill apparatus 23 (hereinafter referred to as a third automatic water mill apparatus 23) located on the left side when seen from the transfer direction performs automatic water milling on the coated surfaces of the left rear door LRD and the left rear fender LRF of the vehicle body V. The automatic water mill device 24 (hereinafter referred to as a fourth automatic water mill device 24) located on the right side when viewed from the transfer direction performs automatic water milling on the coated surfaces of the right rear door RRD and the right rear fender RRF of the vehicle body V.

Since the automatic water mill apparatus 21 to the automatic water mill apparatus 24 have the same configuration, a description will be made here on the representative of the first automatic water mill apparatus 21. In fig. 1, the same means and components among the means and components constituting the automatic water mill apparatus 21 to the automatic water mill apparatus 24 are denoted by the same reference numerals.

Fig. 2 is a schematic configuration diagram showing the first automatic water mill apparatus 21. As shown in fig. 2, the first automatic watermill device 21 comprises an automatic watermill robot 3 and a changer 4. The automatic water mill robot 3 is formed of an articulated robot, and an automatic water mill unit 5 to be described later is mounted on the automatic water mill robot 3. The automatic water mill unit 5 performs automatic water milling on the painting surface of the vehicle body V (in the case of the first automatic water mill apparatus 21, performs automatic water milling on the left front door LFD and the left front fender LFF). The changer 4 replaces the abrasive paper (as referred to as "abrasive slide" in the present invention) mounted on the automatic water mill unit 5. In the following, the automatic watermill robot 3, the automatic watermill unit 5, and the changer 4 will be specifically described.

Automatic water mill robot

As shown in fig. 3, the automatic watermill robot 3 is formed of an articulated robot. Specifically, the automatic watermill robot 3 in the present embodiment includes a rotating base 30, a first arm 31, a second arm 32, a third arm 33, a fourth arm 34, and a fifth arm 35 coupled to each other by joints or the like.

A rotation mechanism (including a motor) rotatable about a vertical axis is housed inside the rotation base 30. A rotation mechanism rotatable about a horizontal axis is accommodated at each joint. The swivel base 30 and the first arm 31, the first arm 31 and the second arm 32, and the third arm 33 and the fourth arm 34 are coupled to each other by having the following joints: the joint has a rotation mechanism that rotates the

arms

31, 32, 33, and 34 relatively. The second arm 32 and the third arm 33, the fourth arm 34 and the fifth arm 35 are coupled to each other by the following rotation mechanism: the rotation mechanism is relatively rotatable about an axis along the extending direction of the arm. The rotational movement of these rotation mechanisms rotates the rotation base 30 or shakes or rotates the arms 31 to 35, which in turn can move the automatic water mill unit 5 to an arbitrary position or change its posture to an arbitrary posture. The rotational movement of each rotation mechanism is performed based on a command signal from a robot controller 83 (see fig. 8) to be described later.

The automatic water mill unit 5 is mounted at the front end of the fifth arm 35. Specifically, the automatic water mill unit 5 is mounted on a frame 36, and the frame 36 is mounted at the front end of the fifth arm 35.

The configuration of the automatic water mill robot 3 is not limited to the above configuration.

Automatic water mill unit

Next, the automatic water mill unit 5 will be described. Fig. 4A is a longitudinal sectional view of the automatic water mill unit 5. Fig. 4B is a schematic diagram showing a disk main body 54a to be described later (a schematic diagram of the disk main body 54a when seen from a direction along its central axis). The longitudinal cross-sectional view of fig. 4A shows a cross-section at a position corresponding to the line IV-IV in fig. 4B.

The posture of the automatic water mill unit 5 (the automatic water mill unit 5 in the first automatic water mill apparatus 21) shown in fig. 4A is a posture in which the grinding paper 56 mounted on the automatic water mill unit 5 faces downward. When the automatic water mill is being performed, the automatic water mill unit 5 is in a posture in which the grinding paper 56 faces the left front door LFD or the painted surface (surface extending in a substantially vertical direction) of the vehicle body V as shown in fig. 3, that is, the automatic water mill unit 5 is rotated about 90 ° from the posture shown in fig. 4A to face the vehicle body V. Therefore, when the automatic water mill is being performed, the downward direction in fig. 4A is a direction facing the vehicle body, and the upward direction in fig. 4A is a direction facing the opposite side to the vehicle body. In the following description of the automatic water mill unit 5 using fig. 4A and 4B, a state in which the automatic water mill unit 5 is in the posture shown in fig. 4A (the posture in which the grinding paper 56 faces downward) will be taken as an example.

As shown in fig. 4A, the automatic water mill unit 5 includes a unit main body 5A and a unit support mechanism 5B mounted on a frame 36. Thus, the unit main body 5A is supported by the automatic water mill robot 3 through the unit support mechanism 5B and the frame 36 (more specifically, is supported at the front end of the fifth arm 35 of the automatic water mill robot 3 through the unit support mechanism 5B and the frame 36).

Unit body

The unit main body 5A includes an air motor (referred to as a "rotary power source" in the present invention) 50, a skirt (referred to as a "housing" in the present invention) 51, a water supply pipe 52, an eccentric head (referred to as a stirring head constituting a "pushing-out device" in the present invention) 53, a disk 54, a cushion pad 55, a grinding paper (referred to as a "grinding slider" in the present invention) 56, a cover 57, a water deflecting member 58, and a sealing member 59.

Pneumatic motor

The air motor 50 includes a drive shaft 50a, and the drive shaft 50a extends downward in the posture shown in fig. 4A. An air supply pipe (not shown) is connected to the air motor 50, and when the air pump (not shown) is activated, the pressure of air supplied through the air supply pipe rotates the driving shaft 50 a. A long and short dashed line O1 in fig. 4A and 4B indicates the rotation center of the drive shaft 50 a.

Skirt portion

The skirt 51 is integrally mounted on the housing 50b of the air motor 50, and an introduction space 51a is formed inside the skirt 51, and water for automatic water mill is introduced into the introduction space 51 a. Specifically, the skirt 51 includes: a cylindrical mounting portion 51b; a skirt main body portion 51c, the diameter of the skirt main body portion 51c increasing from the lower end edge of the mounting portion 51b toward the lower side; and a cap mounting portion 51d extending cylindrically from the lower end edge of the skirt main body portion 51c toward the lower side.

The inner diameter of the mounting portion 51b is substantially equal to the outer diameter of the housing 50b of the air motor 50. The inner peripheral surface of the mounting portion 51b is joined to the outer peripheral surface of the housing 50b of the air motor 50. Thus, the skirt 51 is supported by the air motor 50. Since the diameter of the skirt main body portion 51c increases toward the lower side as described above, the inner diameter of the introduction space 51a inside the skirt main body portion 51c also increases toward the lower side. The cover mounting portion 51d has an annular engagement groove 51e, and the annular engagement groove 51e is recessed from the lower end surface of the cover mounting portion 51d toward the upper side by a predetermined dimension. The engagement groove 51e is used to fix a cover 57 and a seal member 59, which will be described later.

Water supply pipe

The water supply pipe 52 supplies water for the automatic water mill into the introduction space 51a of the skirt 51. The water supply pipe 52 is connected to the water pump 52a (see fig. 8) at an upstream end, is connected to the skirt main body portion 51c of the skirt 51 at a downstream end, and when the water pump 52a is activated, the water supply pipe 52 supplies water for the automatic water mill into the introduction space 51a of the skirt 51.

Eccentric head

The eccentric head 53 is integrated with the driving shaft 50a of the air motor 50, and the eccentric head 53 is formed such that its center is offset from the rotation center O1 of the driving shaft 50 a. Fig. 4A and 4B show a state in which the center of the eccentric head 53 is deviated toward the left side in fig. 4A and 4B. As indicated by the phantom line in fig. 4B, the eccentric head 53 is formed of a generally elliptical disk, and a position (in fig. 4B, an eccentric position on the right side) in the eccentric head 53 that is located outside the center position of the ellipse is located on the rotation center O1 of the drive shaft 50 a. Therefore, when the drive shaft 50a is rotated (about the rotation center O1) upon activation of the air motor 50, the eccentric head 53 eccentrically rotates about the rotation center O1. The imaginary line B in fig. 4B indicates the movement locus of the outer end of the eccentric head 53 (at a position at the outer edge thereof on the deviated side; point C in fig. 4B) when the eccentric head 53 eccentrically rotates. As shown in this imaginary line B, the outer end of the eccentric head 53 (at the position where it is located at the outer edge on the deviated side) is located on the inner peripheral side with respect to the outer peripheral end of a disk hole 54e to be described later.

Disk

The tray 54 includes a tray main body 54a and a tray cover 54b integrally combined.

The disk main body 54a is formed of a metal disk as follows: the metal disk has a larger diameter than the cap mounting portion 51d of the skirt 51. The outer peripheral surface 54c of the disk main body 54a is formed of an inclined surface whose diameter increases downward.

As shown in fig. 4B, the disk main body 54a has a disk center hole 54d, a disk hole 54e, and a communication passage 54f.

The disk center hole 54d is formed by a circular opening opened at a center portion of the disk main body 54 a. The disk center hole 54d extends from the upper surface to the lower surface of the disk main body 54 a.

The disk holes 54e are formed at three positions on the outer peripheral side, each at a predetermined distance from the center of the disk main body 54 a. The disk hole 54e also extends from the upper surface to the lower surface of the disk main body 54 a. The disk holes 54e are provided at positions spaced apart at regular angles in the circumferential direction (positions spaced apart at an angle of 120 °).

The communication passage 54f communicates between the disk center hole 54d and the disk hole 54 e. Specifically, the communication passage 54f extends radially from the center of the disk main body 54a, and communicates with the disk center hole 54d at the inner end portion and communicates with the disk hole 54e at the outer end portion, respectively. The communication passage 54f also extends from the upper surface to the lower surface of the disk main body 54 a.

The tray cover 54b is formed of a metal tray as follows: the outer diameter of the metal disc is substantially equal to the outer diameter of the upper surface of the disc body 54 a. The disk cover 54b has a bearing portion 54g, the bearing portion 54g is a portion provided at the central portion, and at the bearing portion 54g, the plate thickness of the disk cover 54b increases. The bearing portion 54g and the eccentric head 53 are connected to each other by a bearing 53 a. Thus, the disc cover 54b is rotatably supported by the eccentric head 53. For example, when the inner ring of the bearing 53a is coupled to the eccentric head 53 while the outer ring of the bearing 53a is coupled to the bearing portion 54g of the disc cover 54b, the disc cover 54b is rotatably supported by the eccentric head 53.

Further, the tray cover 54b has an opening 54h at a position corresponding to the tray hole 54e of the tray main body 54 a. The inner diameter of the opening 54h is substantially equal to the inner diameter of the disk hole 54 e. The tray cover 54h is joined to the upper surface of the tray main body 54a by means such as screw fastening or welding with the position of the opening 54h coinciding with the position of the tray hole 54 e. This means that the disk center hole 54d and the communication passage 54f are closed at the upper side by the disk cover 54 b. Thus, a water passage 54i is formed in the tray 54, and the water passage 54i continuously passes through the opening 54h of the tray cover 54b, the tray hole 54e, the communication passage 54f, and the tray center hole 54d of the tray main body 54 a. Since the disk cover 54b is coupled to the upper surface of the disk main body 54a as described above, the entire disk 54 is rotatably supported by the eccentric head 53 through the bearing 53 a.

The center position of the disk main body 54A, the center position of the disk cover 54B, the center position of the disk center hole 54d, and the rotation center of the bearing 53a are located on the same axis (see O2 in fig. 4A and 4B). In fig. 4B, the position of the disc 54 at each rotation of the disc 54 by 90 ° around the center position O2 is indicated by a solid line, a broken line, a long-short broken line, and a long-double-short broken line, respectively. The offset dimension of the center position O2 of the disk center hole 54d (the center position of the disk 54) with respect to the rotation center O1 of the drive shaft 50a of the air motor 50 is set to be less than half the inner diameter of the disk center hole 54 d. For example, the inner diameter of the disk center hole 54d is 30mm, and the offset dimension of the center position O2 of the disk center hole 54d with respect to the rotation center O1 of the drive shaft 50a of the air motor 50 is 10mm. These dimensions are not limited to these values.

Cushion pad

A cushion pad 55 is integrally mounted on the lower surface of the tray 54. The cushion pad 55 is formed by a cushion member made of sponge or the like, and has a disk form as follows: the outer diameter of the disc is substantially equal to the outer diameter of the disc body 54 a. The outer peripheral surface 55a of the cushion pad 55 is formed of an inclined surface as follows: the diameter of the inclined surface decreases towards the lower side.

As shown in fig. 4A, the cushion pad 55 has a pad center hole 55b in a center portion thereof, the pad center hole 55b being formed of a circular opening. The cushion center hole 55b extends from the upper surface to the lower surface of the cushion pad 55. The center position of the pad center hole 55b coincides with the center position of the disk center hole 54 d. Thus, the pad center hole 55b communicates with the water passage 54i formed in the disk 54. The inner diameter of the pad center hole 55b is slightly larger than the inner diameter of the disk center hole 54 d. For example, the inner diameter of the disk center hole 54d is 30mm, and the inner diameter of the pad center hole 55b is 35mm. These dimensions are not limited to these values.

Grinding paper

The abrasive paper 56 is detachably mounted on the lower surface of the cushion pad 55. Specifically, the lower surface 56a of the grinding paper 56 (the surface facing the vehicle body V during the automatic water grinding) is a grinding surface. For example, the abrasive surface comprises a resin. On the other hand, the upper surface 56b (surface mounted to the lower surface of the cushion pad 55) is mounted to the lower surface of the cushion pad 55 by a hook and loop fastener such as a velcro (R).

The abrasive paper 56 has a paper center hole 56c at its center portion, the paper center hole 56c being formed by a circular opening. In a state where the abrasive paper 56 is mounted at a correct position on the lower surface of the cushion pad 55, the center position of the paper center hole 56c coincides with the center position of the pad center hole 55 b. The inner diameter of the paper center hole 56c may be set equal to the inner diameter of the pad center hole 55b or slightly larger than the inner diameter of the pad center hole 55 b.

Cover for vehicle

The cover 57 is a member that is installed at the lower end of the skirt 51 and prevents scattering of water released toward the outer periphery of the disc 54 after being introduced into the introduction space 51a of the skirt 51 (release of the water will be described later). Specifically, the cover 57 includes: a cylindrical mounting portion 57a; a cover main body 57b whose diameter increases from the lower end edge of the mounting portion 57a toward the lower side; and a water deflector 57c extending obliquely downward from a lower end edge of the cover main body 57 b.

The diameter of the mounting portion 57a is substantially equal to the diameter of the engagement groove 51e formed in the skirt portion 51. When the mounting portion 57a is inserted into the engagement groove 51e, the cover 57 is supported by the skirt portion 51.

The outer diameter of the cover main body 57b is set slightly larger than the outer diameter of the disk 54.

The water deflector 57c is formed of: the portion is slightly curved downward from the outer peripheral end of the cover main body 57 b.

Water deflection member

The water deflecting member 58 is mounted on the water deflecting portion 57c of the cover 57 and is inclined toward the inner peripheral side (so that the diameter is reduced) while extending downward from the lower end edge of the water deflecting portion 57 c. The water deflecting member 58 is mounted on the water deflecting portion 57c by means such as bonding or screw fastening.

Sealing member

Similar to the cap 57, a sealing member 59 is mounted at the lower end of the skirt 51. Specifically, the seal member 59 is formed of a flat cylindrical member made of urethane. The diameter of the seal member 59 is substantially equal to the diameter of the engagement groove 51e formed in the skirt 51. When the upper end portion of the seal member 59 is inserted into the engagement groove 51e while overlapping the mounting portion 57a of the cap 57, the seal member 59 is supported by the skirt portion 51.

The height of the seal member 59 is substantially equal to the size of the gap between the top inside the engagement groove 51e and the upper surface of the disk 54. Therefore, when no external pressure (e.g., water pressure) acts on the sealing member 59, the lower end of the sealing member 59 is in contact with the upper surface of the disk 54 along the entire circumference of the sealing member 59 (without a gap), as shown in fig. 4A. Therefore, the introduction space 51a of the skirt 51 can become a sufficiently sealed space. When a water pressure acts on the inner side of the sealing member 59 and the water pressure exceeds a predetermined value, the sealing member 59 is elastically deformed and a small gap is formed between the lower end of the sealing member 59 and the upper surface of the disc 54, through which water flows.

Unit supporting mechanism

Next, the unit support mechanism 5B will be described. As mentioned above, the unit support mechanism 5B is a mechanism that supports the unit main body 5A onto the automatic watermill robot 3 through the frame 36.

As shown in fig. 3 and 4A, the unit support mechanism 5B includes a pair of cylinders 60. As shown in fig. 3, the cylinders 60 are mounted on both side surfaces (upper and lower surfaces in fig. 3) of the frame 36, respectively. A piston rod 61A and two guide rods 61B (see fig. 2) protrude from the cylinder 60 to be movable forward and backward. The automatic water mill unit 5 includes a unit case 5C (see imaginary line in fig. 4A), and the unit case 5C covers the outside of the skirt 51 and the air motor 50. As shown in fig. 4A, the lower end of the piston rod 61A and the lower end of the guide rod 61B are connected to the support block 62. A coupling rod 63 extends from the lower surface of each support block 62. A cylindrical rod end 64 is provided at the lower end of the coupling rod 63. The rod end 64 has a bolt insertion hole 64a at its center, the bolt insertion hole 64a extending through the rod end 64 in the horizontal direction. A fastening nut 65 is mounted on the outer surface of the unit housing 5C at a position where the fastening nut 65 faces the rod end 64. The bearing bolts 66 are screwed into the bolt insertion holes 64a of the rod ends 64 and the screw holes 65a of the fastening nuts 65 from the outside, whereby the unit case 5C is rotatably supported by the rod ends 64. Thus, during automatic water milling, rotating the unit housing 5C relative to the rod end 64 may rotate the entire automatic water milling unit 5 and thereby deflect the direction of the disc 54 and the cushion 55 to a direction along the coated surface of the vehicle body V. Therefore, a wide area of the polishing surface (lower surface) 56a of the polishing paper 56 can be brought into contact with the coated surface of the vehicle body V.

Replacing device

Next, the changer 4 will be described. As shown in fig. 2, the changer 4 includes a paper peeling unit 41, a pad cleaning unit 42, a pad drainage unit 43, a paper mounting unit 44, and a paper inspection unit 45.

Paper stripping unit

After the completion of the automatic water mill, the paper peeling unit 41 peels (removes) the grinding paper 56 of the automatic water mill unit 5 from the cushion pad 55. If the same abrasive paper 56 is used (without replacing the abrasive paper 56) to perform the automatic water-milling on a plurality of vehicle bodies V, the milling efficiency may be lowered, or the paint of the vehicle body V that has previously undergone the automatic water-milling may be transferred to the subsequent vehicle body V. To avoid this, the grinding paper 56 is replaced each time after finishing the automatic water-grinding of one vehicle body V. The paper peeling unit 41 performs a step of peeling the abrasive paper 56 from the cushion pad 55 to replace the abrasive paper 56.

The paper peeling unit 41 includes a grip shaft 41a and a grip claw 41b. The clamp shaft 41a is formed of a metal shaft supported by the frame 41c so as to be rotatable about a horizontal axis. The clamp shaft 41a is coupled to the clamp shaft motor 41d and is configured to be rotatable when the clamp shaft motor 41d is activated. The grip finger 41b is disposed above the grip shaft 41a and in proximity to the grip shaft 41a. Thus, the gripper jaw 41b can clamp the abrasive paper 56 between the gripper jaw 41b and the gripper shaft 41a.

The grinding paper collection box 41e is installed below the holding shaft 41a, and the grinding paper 56 peeled off from the cushion pad 55 falls into the grinding paper collection box 41e to be collected.

Pad cleaning unit

The pad cleaning unit 42 cleans the cushion pad 55 from which the abrasive paper 56 has been peeled off by the paper peeling unit 41. After the automatic water mill, a paint (paint separated from the vehicle body V by grinding; grinding dust) adheres to the grinding paper 56 and the cushion pad 55. Therefore, even after the grinding paper 56 is replaced, if the subsequent vehicle body V is automatically water-ground without cleaning the cushion pad 55, the paint may be transferred to the vehicle body V. The pad cleaning unit 42 is installed to avoid such a situation.

As shown in fig. 5, the pad cleaning unit 42 includes a cleaning tank 42a, a water supply pipe 42b, and a circulation circuit 42c. The cleaning groove 42a has an inner diameter larger than an outer diameter of the automatic water mill unit 5. A metal mesh 42d extending in the horizontal direction is provided inside the cleaning tank 42a at an intermediate point in the vertical direction (depth direction).

The water supply pipe 42b is connected to the water supply pump 42j (see fig. 8) at an upstream end, is connected to the cleaning tank 42a at a downstream end, and supplies cleaning water (pure water) to the cleaning tank 42a when the water supply pump 42j is activated. A valve 42e for adjusting the water supply is provided on the water supply pipe 42 b.

The circulation circuit 42c has a configuration in which a circulation pump 42g and a filter 42h are provided on the path of the circulation pipe 42 f. One end (upstream end) of the circulation pipe 42f is connected to the bottom of the cleaning tank 42a and the other end (downstream end) is connected to the side surface of the cleaning tank 42a. During cleaning of the pad, the following water circulation action is performed: in this water circulation action, the circulation pump 42g is activated to draw water from the bottom of the cleaning tank 42a, and the water is purified by the filter 42h, and then returned to the cleaning tank 42a through the side surface. The drain valve 42i is connected to the filter 42h. The drain valve 42i is opened to drain water from the cleaning tank 42a.

Pad drainage unit

The pad drainage unit 43 drains the cushion pad 55 that has been cleaned by the pad cleaning unit 42.

As shown in fig. 6, the pad drain unit 42 includes a drain table 43a and a blast nozzle 43b. The drain table 43a includes a rack frame 43c and a mesh-shaped inclined plate 43 mounted on the rack frame 43 c. To drain the cushion pad 55, the automatic water mill robot 3 is operated to press the cushion pad 56 against the inclined plate 43d of the drain table 43a, whereby water is squeezed out of the cushion pad 55. During the drainage, air is blown from the air blowing nozzle 43b toward the cushion pad 55 to increase drainage efficiency. A blower motor 43e (see fig. 8) is connected to the blower nozzle 43b.

The cushion pad 55 may be pressed against the inclined plate 43d of the drain table 43a so that the entire cushion pad 55 is uniformly pressed against the inclined plate 43 d. However, it is preferable to change the position where the cushion pad 55 is pressed against the inclined plate 43d in the circumferential direction of the cushion pad 55, because this can further increase the drainage efficiency. Specifically, by moving the center line O2 (center position) of the cushion pad 55 and the disk 54 as indicated by the arrow in fig. 6, the position at which the cushion pad 55 is pressed against the inclined plate 43d is changed in the circumferential direction.

Paper mounting unit

The paper mounting unit 44 mounts a new abrasive paper 56 onto the cushion pad 55 that has been drained by the pad drain unit 43.

As shown in fig. 2, the paper mounting unit 44 includes a paper holder 44a and a paper pressing plate 444b. A plurality of unused abrasive papers 56 are placed on the paper holder 44a on top of each other. Each piece of grinding paper 56 is placed on the paper holder 44a in such a manner that the surface having the hook and loop fastener to be mounted to the cushion pad 55 faces upward.

The platen 44b is connected with a cylinder 44c. The air cylinder 44c is activated to move the platen 44b between a position where the platen 44b presses the upper side of the grinding paper 56 and a position where the platen 44b is retracted from the grinding paper 56. The paper pressing plate 44b has a U-shaped cutout 44d, and when the paper pressing plate 44b is located at a position where the paper pressing plate 44b presses the upper side of the grinding paper 56 as shown in fig. 2, a portion of the hook and loop fastener of the grinding paper 56 is exposed upward. In this state, the cushion pad 55 is pressed against the upper surface of the grinding paper 56, and then the paper pressing plate 44b is retracted from the grinding paper 56, so that the entire hook and loop fastener of the grinding paper 56 is mounted to the cushion pad 55.

Paper inspection unit

In a state where the abrasive paper 56 has been mounted on the cushion pad 55 by the paper mounting unit 44, the paper checking unit 45 checks whether the mounting position of the abrasive paper 56 is a correct position.

As shown in fig. 7, the paper inspection unit 45 includes a bracket 45a and a camera 45b. The bracket 45a includes: a pair of plates 45c (see fig. 2) disposed at intervals substantially equal to the outer diameter of the cushion pad 55; and a positioning plate 45d that couples together the ends of the plate 45c on one side. The camera 45b is disposed below the holder 45a, and captures an image of the cushion pad 55 (with the abrasive paper 56 mounted thereon) placed on the holder 45 a. The posture of the camera 45b is set such that the center line O2 of the cushion pad 55 in a state of being placed on the holder 45a and the center line of the camera 45b coincide with each other. Whether the mounting position of the abrasive paper 56 is the correct position is checked by using data of images of the cushion pad 55 and the abrasive paper 56 taken by the camera 45b.

Control system

Next, a control system of the automatic water mill apparatus 21 to the automatic water mill apparatus 24 will be described. Fig. 8 is a block diagram showing a control system of the automatic water mill apparatus 21 to the automatic water mill apparatus 24.

As shown in fig. 8, the control system of the automatic water mill apparatus 21 to the automatic water mill apparatus 24 has the following configuration: in this configuration, the start switch 81, the conveyor controller 82, the robot controller 83, the automatic water mill unit controller 84, and the changer controller 85 are electrically connected to the central processing unit 8, and the central processing unit 8 comprehensively controls the automatic water mill apparatus 21 to the automatic water mill apparatus 24 so that various signals including instruction signals can be transmitted and received between the central processing unit 8 and these components.

The start switch 81 transmits a command signal for starting the automatic water mill apparatus 21 to the automatic water mill apparatus 24 to the central processing unit 8 according to the operation of the worker. When this start instruction signal is received, the automatic water mill apparatus 21 to the automatic water mill apparatus 24 are started (activated) to start an automatic water mill operation which will be described later.

The conveyor controller 82 controls the transfer of the vehicle body V by the conveyor 11. Specifically, the conveyor controller 82 operates the conveyor 11 until the vehicle body V, which is the object of the automatic water mill, reaches a predetermined position (position shown in fig. 1) in the automatic water mill shop 1, and temporarily stops the conveyor 11 at this point of time. When a predetermined time elapses after the completion of the automatic water mill by the automatic water mill apparatus 21 to the automatic water mill apparatus 24, the conveyor controller 82 operates the conveyor 11 again to transfer the vehicle body V subjected to the automatic water mill to the next shop, and operates the conveyor 11 until the vehicle body V as the next object of the automatic water mill reaches a predetermined position in the automatic water mill shop 1.

The robot controller 83 controls the automatic water mill robots 3 of the respective automatic water mill apparatuses 21 to 24. The robot controller 83 transmits command signals to various motors M provided in the rotation mechanism of each of the automatic water mill robots 3 according to teaching information previously executed on the automatic water mill robots 3. Accordingly, the robot controller 83 controls the position of the automatic water mill unit 5 based on the teaching information.

The automatic water mill unit controller 84 controls the automatic water mill unit 5. The water pump 52a, the air motor 50 and the air cylinder 60 are connected to the automatic water mill unit controller 84.

The water pump 52a is activated according to a command signal from the automatic water mill unit controller 84, and supplies water for the automatic water mill to the introduction space 51a of the skirt portion 51 through the water supply pipe 52. The air motor 50 is activated in accordance with a command signal from the automatic watermill unit controller 84 and rotates the drive shaft 50 a. The cylinder 60 is activated according to a command signal from the automatic water mill unit controller 84, and moves the piston rod 61A back and forth. Thus, the automatic water mill unit 5 is moved back and forth and its posture is changed.

The changer controller 85 controls the units 41 to 45 of the changer 4. The grip shaft motor 41d, the water supply pump 42j, the circulation pump 42g, the drain valve 42i, the blower motor 43e, the cylinder 44c, and the camera 45b are connected to the changer controller 85.

In the step of peeling the abrasive paper 56 from the cushion pad 55 by the paper peeling unit 41, the grip shaft motor 41d is activated by a command signal from the changer controller 85, and rotates the grip shaft 41 a. In the step of cleaning the cushion pad 55 by the pad cleaning unit 42, the water supply operation by the water supply pump 42j, the water circulation operation by the circulation pump 42g, and the water discharge operation by the drain valve 42i are performed according to the instruction signal from the changer controller 85. In the step of draining the cushion pad 55 by the pad drain unit 43, the blower motor 43e is activated by a command signal from the changer controller 85 and blows air toward the cushion pad 55. In the step of mounting the grinding paper 56 to the cushion pad 55 by the paper mounting unit 44, the air cylinder 44c is activated by a command signal from the changer controller 85, and the paper pressing plate 44b moves between a position where the paper pressing plate 44b presses the upper side of the grinding paper 56 and a position where the paper pressing plate 44b is retracted from the grinding paper 56.

The changer controller 85 receives photographing data (data of an image of the cushion pad 55 on which the abrasive paper 56 is mounted) from the camera 45b provided in the paper inspection unit 45, and determines whether the abrasive paper 56 is mounted at the correct position.

Automatic water mill operation

Next, an automatic water mill operation performed on the vehicle body V in the automatic water mill shop 1 configured as described above will be described.

Fig. 9 is a flowchart showing an automatic water-milling operation performed by the first automatic water-milling apparatus 21. The same automatic water mill operation is performed simultaneously in the other automatic water mill apparatuses 22 to 24.

As shown in fig. 9, in the automatic water mill operation by the first automatic water mill apparatus 21, the following steps are sequentially performed after "carry-in car body: pad wetting step, front door automatic water grinding step, front fender automatic water grinding step, start to move out of the car body, paper peeling step, pad cleaning step, pad draining step, paper mounting step, and paper inspection step.

Carry-in vehicle body

In the step of carrying in the vehicle body, the conveyor 11 is activated by a command signal from the conveyor controller 82, and the vehicle body V, which is the object of the automatic water mill, is transferred to a predetermined position (position shown in fig. 1) in the automatic water mill shop 1. Then, the conveyor 11 is stopped. The conveyor 11 is kept in a stopped state until a predetermined time elapses, at which time the automatic water milling by each of the automatic water milling apparatuses 21 to 24 is completed.

Pad wetting step

In the pad wetting step, the automatic water mill robot 3 is operated by a command signal from the robot controller 83, and the automatic water mill unit 5 is immersed in the water stored in the cleaning tank 42a of the pad cleaning unit 42. Specifically, the water supply pump 42j is activated by a command signal from the changer controller 85, water is supplied to the cleaning tank 42a, and the automatic water mill unit 5 is immersed in the water inside the cleaning tank 42a in the case where the water is thus stored in the cleaning tank 42 a. In this way, the abrasive paper 56 and the buffer pad 55 are wetted before the automatic water mill process is started.

Front door automatic water mill step

In the front door automatic water mill step, the automatic water mill robot 3 is operated to move the automatic water mill unit 5 to a position where it faces the front door (left front door LFD in the case of the first automatic water mill apparatus 21) (see fig. 3). Then, the automatic water mill unit 5 is activated by a command signal from the automatic water mill unit controller 84.

Specifically, the water pump 52a is activated to supply water for the automatic water mill to the introduction space 51a of the skirt 51 through the water supply pipe 52.

Further, the air motor 50 is activated to rotate the drive shaft 50 a. As the driving shaft 50a rotates, the eccentric head 53 eccentrically rotates in the introduction space 51a of the skirt 51. The eccentric head 53 eccentrically rotates in the water present in the introduction space 51a. As the water introduced into the space 51a is thus stirred, the water pressure introduced into the space 51a becomes high. As described above, the introduction space 51a communicates with the water passage 54i, the communication passage 54f, and the disk center hole 54d of the disk main body 54a, which continuously pass through the opening 54h and the disk hole 54e of the disk cover 54 b. Accordingly, the water stirred in the introduction space 51a is pushed out to the opening 54h of the tray cover 54 b. Fig. 10 is a sectional view showing the flow of water in the automatic water mill unit 5 in a state where automatic water milling is performed. (fig. 10 is a view of a cross section at a position corresponding to the line X-X in fig. 4B.) as indicated by an arrow W1 in fig. 10, water pushed out from the introduction space 51a to the opening 54h of the tray cover 54B flows through the tray hole 54e, the communication passage 54f, and the tray center hole 54d from the opening 54h. The water having passed through the disk center hole 54d passes through the pad center hole 55b of the cushion pad 55, and is pumped toward the coated surface of the vehicle body V through the paper center hole 56c of the abrasive paper 56. Then, during the automatic water-milling process, the water flows into the gap between the polishing surface 56a and the coated surface of the polishing paper 56, and is pushed out from the center portion of the polishing paper 56 toward the outer peripheral side between the polishing surface 56a and the coated surface.

In a state where water thus flows, the abrasive surface 56a of the abrasive paper 56 is pressed against the coated surface with a predetermined pressure, and in a state where water flows between the abrasive surface 56a and the coated surface, the automatic water mill robot 3 is operated to move the abrasive paper 56 along the coated surface of the left front door LFD to grind the coated surface.

Since the disk 54 is rotatably supported by the eccentric head 53 as described above, the disk 54, the cushion pad 55, and the abrasive paper 56 perform eccentric motion (the motion in which the center point of the disk 54 performs a circling movement) about the rotation center O1 of the drive shaft 50a, without being forced to spin when the eccentric head 53 eccentrically rotates.

Fig. 11 is a side view of the vehicle body, showing a moving path of the automatic water mill unit 5 in the automatic water mill operation. Arrow D1 in fig. 11 is one example of the moving path of the automatic water mill unit 5 when the automatic water mill unit 5 of the first automatic water mill apparatus 21 grinds the coated surface of the left front door LFD. Arrow D2 is one example of a moving path of the automatic water mill unit 5 when the automatic water mill unit 5 of the first automatic water mill apparatus 21 grinds the painted surface of the left front fender LFE (when the automatic water mill unit 5 performs a front fender automatic water mill step which will be described later). Arrow D3 is one example of the moving path of the automatic water mill unit 5 when the automatic water mill unit 5 of the third automatic water mill apparatus 23 grinds the coated surface of the left rear fender LRF. Arrow D4 is one example of a moving path of the automatic water mill apparatus 5 when the automatic water mill unit 5 of the third automatic water mill apparatus 23 grinds the coated surface of the left rear door LRD.

While the painting surface of the left front door LFD is automatically watermill by the automatic watermill unit 5 of the first automatic watermill device 21, the painting surface of the left rear fender LRF is automatically watermill by the automatic watermill unit 5 of the third automatic watermill device 23. While the automatic water-grinding of the painting surface of the left front fender LFF is performed by the automatic water-grinding unit 5 of the first automatic water-grinding apparatus 21, the automatic water-grinding of the painting surface of the left rear door LRD is performed by the automatic water-grinding unit 5 of the third automatic water-grinding apparatus 23. This is to prevent the automatic water milling robot 3 of the first automatic water milling apparatus 21 and the automatic water milling robot 3 of the third automatic water milling apparatus 23 from being too close to each other during the automatic water milling.

Since in the automatic water mill, water is pushed out toward the coated surface via the disk center hole 54d and the pad center hole 55b as described above, the automatic water mill is performed while water is pushed out toward the outer peripheral side from the center portion of the polishing paper 56 between the polishing paper 56 and the coated surface. Therefore, the polishing dust generated by the automatic water mill is washed away toward the outer peripheral side by the water pushed toward the outer peripheral side so that the polishing dust does not remain around the polishing paper 56. Therefore, the automatic water mill can be performed with reduced possibility of clogging due to the grinding dust.

The flow of water inside the tray 54 and the cushion 55 will be described in detail below. Fig. 12 is a sectional view showing the flow of water inside the tray 54 and the cushion 55. As shown in fig. 12, as the eccentric head 53 eccentrically rotates, water that has been pushed out into the opening 54h of the disk cover 54b flows through the communication passage 54f via the disk hole 54e, thereby flowing toward the central portion of the disk main body 54 a. After reaching the disk center hole 54d of the disk main body 54a, water flows from the disk center hole 54d into the pad center hole 55b of the cushion pad 55. Here, the water hits the inner wall surface of the pad center hole 55b and forms a swirling flow moving along the inner surface. Specifically, since the disk main body 54a is provided with the disk holes 54e and the communication passages 54f at three positions, water flows into the disk center hole 54d from three directions, and these water flows will merge with each other in the disk center hole 54d, and then move to the pad center hole 55b to form a swirling flow. As described above, the inner diameter of the pad center hole 55b is slightly larger than the inner diameter of the disk center hole 54 d. Therefore, when water is pushed out from the relatively small-diameter disc center hole 54d toward the relatively large-diameter pad center hole 55b, the water is subjected to a large centrifugal force in the pad center hole 55b, which can enhance the pressure of the water pushed out from the pad center hole 55b toward the coated surface. This also helps to wash away the abrasive dust effectively toward the outer peripheral side, thereby reliably reducing the possibility of clogging due to the abrasive dust.

The following flow of water also occurs inside the automatic water mill unit 5. As the water introduced into the space 51a is stirred by the eccentric rotation of the eccentric head 53, the water pressure rises and acts on the sealing member 59. As shown in fig. 4A, the upper end portion of the seal member 59 is inserted and supported in the engagement groove 51e of the skirt 51, while the lower end portion of the seal member 59 is not supported and is in contact with the upper surface of the disk 54 along the entire circumference of the seal member 59. Therefore, when a water pressure acts on the seal member 59 and the water pressure exceeds a predetermined value, the lower end portion of the seal member 59 is elastically deformed toward the outer peripheral side, leaving a small gap between the lower end of the seal member 59 and the upper surface of the disk 54. Through which water flows. Arrow W2 in fig. 10 indicates this flow of water. The water flowing out toward the outer peripheral side through the gap between the sealing member 59 and the disk 54 thereby collides with the water deflecting portion 57c of the cover 57, and the flow direction thereof is changed to a direction toward the application surface of the vehicle body V. Then, the water collides with the water deflecting member 58 and changes its flow direction so as to be directed toward the center side (toward the side of the cushion pad 55) while flowing toward the coated surface of the vehicle body V. The inner surfaces of the hood 57 and the inner surfaces of the water deflecting member 58 are cleaned by the flow of the water, and the abrasive dust (if any) adhering to these inner surfaces is removed. Then, the water collides with and is sent (flicked) back by the coated surface of the vehicle body V, and changes its flow direction while flowing away from the coated surface of the vehicle body V, so that the water is directed toward the center side (toward the side of the disk 54, see arrow W3 in fig. 10). Since the flow direction of the water is thus changed, the water flowing out toward the outer peripheral side through the gap between the sealing member 59 and the disk 54 is not widely scattered at the peripheral portion of the automatic water mill unit 5. Therefore, the paint separated from the vehicle body V by the automatic water mill is less likely to adhere to a wide area of the vehicle body V.

Automatic water grinding step for front fender

When the front door automatic water-milling step is completed, the operation of the automatic water-milling unit 5 is temporarily stopped, and then the front fender automatic water-milling step is started. In the front fender automatic water milling step, the automatic water milling robot 3 is operated to move the automatic water milling unit 5 to a position where the automatic water milling unit 5 faces the front fender (in the case of the first automatic water milling apparatus 21, the left front fender LFF). Then, the automatic water mill unit 5 is activated by a command signal from the automatic water mill unit controller 84. The operation of the automatic water mill unit 5 in this step is the same as the front door automatic water mill step described above, and thus will not be described again here.

Begin to move out of the vehicle body

When the front door automatic water mill step is completed, the operation of the automatic water mill unit 5 is stopped and the vehicle body V starts to be carried out. Specifically, the conveyor 11 is activated to shift the vehicle body V that has undergone the automatic water mill toward the next shop.

Paper peeling step

As the carriage V starts to be carried out, the paper separation step is performed by the paper separation unit 41 provided in the changer 4. In the paper peeling step, the automatic water mill robot 3 is operated to move the automatic water mill unit 5 to a position where the grinding paper 56 is sandwiched between the sandwiching shaft 41a and the sandwiching claw 41b, and then, the automatic water mill unit 5 is moved upward to thereby peel the grinding paper 56 from the cushion pad 55. Thereafter, the grip shaft motor 41d is activated to rotate the grip shaft 41a, so that the abrasive paper 56 peeled off from the cushion pad 55 falls into the abrasive paper collection box 41e to be collected.

Pad cleaning step

In the pad cleaning step by the pad cleaning unit 42, as the water supply pump 42j is activated, cleaning water (pure water) is supplied to the cleaning tank 42a, and the water circulates through the circulation loop 42c as the circulation pump 42g is activated. In this state, the automatic water mill robot 3 is operated to move the automatic water mill unit 5 into the cleaning tank 42a, and the cushion pad 55 is pressed against the metal mesh 42d to squeeze out water (water in which paint is mixed) contained in the cushion pad 55. Then, the automatic water mill unit 5 is slightly lifted to separate the cushion pad 55 from the metal mesh 42 d. In this state, the air motor 50 is activated, and the cushion pad 55 is rotated (eccentrically rotated) in the water to clean the cushion pad 55. As the circulation pump 42g operates during these actions, the water circulates by being drawn out from the bottom of the cleaning tank 42a, purified by the filter 42h, and then returned to the cleaning tank 42a through the side surface of the cleaning tank 42 a. Thereafter, the automatic water mill unit 5 is further slightly raised to move the cushion pad 55 above the water level in the cleaning tank 42a, and the air motor 50 is activated again to drain the cushion pad 55 using centrifugal force. At the same time, the drain valve 42i is opened to drain water from the cleaning tank 42 a.

Pad drainage step

In the pad drainage step by the pad drainage unit 43, the automatic water mill robot 3 is operated to press the cushion pad 55 against the inclined plate 43d of the drainage table 43a, thereby squeezing water out of the cushion pad 55. In this process, the center line O2 of the disk 54 and the cushion pad 55 moves as indicated by the arrow in fig. 6, thereby changing the position in the circumferential direction of the cushion pad 55 at which the cushion pad 55 is pressed against the inclined plate 43 d. During the drainage, the blower motor 43e is activated to blow air from the blower nozzle 43b toward the cushion pad 55, thereby improving drainage efficiency.

Paper mounting step

In the paper mounting step by the paper mounting unit 44, with the paper pressing plate 44b pressing the upper side of the grinding paper 56 as shown in fig. 2, the automatic water mill robot 3 is operated to press the cushion pad 55 against the upper surface of the grinding paper 56. In this state, the air cylinder 44c is activated to move the platen 44b away from the grinding paper 56, thereby mounting the entire hook and loop fastener of the grinding paper 56 to the cushion pad 55. Since the cushion pad 55 is rotatably supported by the bearing 53a, it is preferable that the cushion pad 55 is pressed against a positioning plate (not shown) at a stage before the paper mounting step to adjust the posture of the cushion pad 55 with respect to the rotation center O1 of the drive shaft 50a (the phase of the cushion pad 55 in the deviating direction) to a correct posture.

Paper inspection step

In the paper inspection step by the paper inspection unit 45, the automatic water mill robot 3 is operated to place the cushion pad 55 (on which the grinding paper 56 is mounted) on the bracket 45a as shown in fig. 7, and press the outer peripheral surface of the cushion pad 55 against the plate 45c and the positioning plate 45 d. In this state, images of the cushion pad 55 and the polishing paper 56 are taken from below by the camera 45 b. The photographing data is transmitted to the central processing unit 8 through the changer controller 85, and the central processing unit 8 checks whether the installation position of the abrasive paper 56 is a correct position. When it is determined that the mounting position of the abrasive paper 56 is the correct position, the automatic water mill operation from the pad wetting step is performed on the next vehicle body V that has been transferred to the predetermined position in the automatic water mill shop 1 by the step of carrying in the vehicle body. On the other hand, when it is determined that the mounting position of the abrasive paper 56 is not the correct position, the mounting operation of the abrasive paper 56 is re-performed. In order to re-perform the mounting action, for example, a paper peeling step and a paper mounting step are sequentially performed.

The actions from "carry-in car body" to "paper inspection step" are repeatedly performed to sequentially perform the automatic water mill for each car body V transferred to the automatic water mill shop 1.

Advantages of the embodiments

In the above embodiment, the disk center hole 54d is formed at the center portion of the disk 54, and the pad center hole 55b is formed at the center portion of the cushion pad 55. The water in the introduction space 51a inside the skirt 51 is stirred as the eccentric head 53 eccentrically rotates, and is thereby pushed out toward the application surface 2 via the disk center hole 54d and the pad center hole 55b with increased pressure. Therefore, the polishing dust caused by the automatic water mill can be washed away toward the outer peripheral side by the water pushed toward the outer peripheral side, so that the possibility of clogging due to the polishing dust can be reduced, and high polishing efficiency can be maintained.

In the embodiment, the outer end of the eccentric head 53 (at a position where it is located at the outer edge of the deviated side; point C in fig. 4B) is located on the inner peripheral side with respect to the outer peripheral end of the disk hole 54 e. Therefore, a situation in which the eccentric head 53 temporarily covers the entire disk hole 54e while rotating (eccentrically) does not occur. In other words, at least a portion of each disk hole 54e is always in communication with the introduction space 51 a. Therefore, the water passage 54i through which the water having been supplied to the introduction space 51a is pushed out toward the coated surface can be always ensured, so that the water can be stably pushed out toward the coated surface, and an effect of reducing the possibility of clogging can be stably produced.

In the embodiment, when the water pressure introduced into the space 51a increases, the sealing member 59 is elastically deformed to leave a gap between the sealing member 59 and the disc 54, and water flows through the gap. Thus, during the automatic water mill operation, a high water pressure may be maintained in the introduction space 51a, which may help to enhance the pressure of water pushed out of the pad center hole 55b toward the coated surface. In this state, a water film (flowing water) exists between the sealing member 59 and the disk 54. Therefore, even when the disk 54 and the seal member 59 move relative to each other as the disk 54 rotates, the sliding resistance does not increase, so that relative movement can be allowed with little frictional loss. Further, the presence of the sealing member 59 makes it possible to push out water while accumulating water in the introduction space 51 a. Accordingly, a situation in which water that has been introduced into the introduction space 51a through the water supply pipe 52 is directly released can be avoided, which can cause a significant reduction in the amount of water used for the automatic water mill, and thus a reduction in the running cost. Since the amount of water used is significantly reduced, the amount of water scattered to the peripheral portion of the automatic water mill unit 5 can be reduced, and thus the possibility of the grinding dust adhering to a wide area of the vehicle body V can be reduced.

In the embodiment, the center position O2 of the disk center hole 54d (the center position of the disk 54) is set to a size deviated from the rotation center O1 of the drive shaft 50a of the air motor 50 by less than half the inner diameter of the disk center hole 54 d. Therefore, in the case where the disk 54 is eccentrically rotated with respect to the drive shaft 50a, even when the disk center hole 54d moves as the disk 54 eccentrically rotates, the water flow passage inside the disk center hole 54d can be maintained with a region (see region E in fig. 4B) in which the flow of water is not disturbed by the movement of the inner wall of the disk center hole 54d, and water can stably flow in the region E. Therefore, the water can be pushed out toward the coated surface while maintaining a high pressure. This also helps to wash away the abrasive dust effectively toward the outer peripheral side, thereby reliably reducing the possibility of clogging due to the abrasive dust.

Modified example 1

Next, modified example 1 will be described. In the above-described embodiment, when the eccentric head 53 is eccentrically rotated by the air motor 50, the water in the introduction space 51a inside the skirt portion 51 is stirred, and thereby the water is pushed out toward the application surface via the disk center hole 54d and the pad center hole 55b with an enhanced pressure. Thus, the air motor 50 and the eccentric head 53 constitute what is called "ejector" in the present invention.

In this modified example, instead of the push-out device, a cylinder for pushing out water is accommodated inside the introduction space 51 a. In other words, the cylinder constitutes what is called "ejector" in the present invention. The components other than the ejector (cylinder) are the same as those in the above embodiment, and therefore only the ejector will be described here.

Fig. 13 is a longitudinal sectional view (corresponding to fig. 4A) of the automatic water mill unit 5 in this modified example 1. As shown in fig. 13, in the automatic water mill unit 5 of this modified example, the cylinder 9 for pushing out water is accommodated in the introduction space 51a of the skirt 51. The cylinder 9 is of a reciprocating or rotating type that is powered by the air motor 50 to suck water from the intake space 51a and discharge water toward the disk center hole 54 d. Accordingly, the disc 54 is configured such that the disc center hole 54d is opened directly to the introduction space 51a or the discharge port of the cylinder 9. For example, when the water flow W2 (water flow passing between the lower end of the sealing member 59 and the upper surface of the disk 54 and cleaning the inner surface of the cover 57 and the inner surface of the water deflecting member 57) described in this embodiment is required, a configuration is adopted in which the discharge port of the cylinder 9 is opened to the introducing space 51a, and when the water flow W2 is not required, a configuration is adopted in which the discharge port of the cylinder 9 is directly opened to the disk center hole 54 a. The configuration for pushing out water using the cylinder 9 is not limited to these configurations.

In such a configuration, the water is forced to be discharged toward the disc center hole 54d as the cylinder 9 is activated, and therefore, the water having a high pressure is pushed out toward the coated surface of the vehicle body V via the disc center hole 54d, the pad center hole 55b, and the paper center hole 56 c. Therefore, also in this modified example, the grinding dust caused by the automatic water mill can be washed away toward the outer peripheral side by the water pushed out toward the outer peripheral side, so that the possibility of clogging due to the grinding dust can be reduced, and high grinding efficiency can be maintained.

Modified example 2

A modified example 2 will be described. This modified example is different from the embodiment in the configuration of the unit support mechanism 5B. Therefore, differences from the embodiments will be mainly described herein.

Fig. 14 is a side view of the automatic water mill unit 5 in this modified example. Fig. 15 is a cross-sectional view showing the floating joint structure of the rod end 64 in this modified example. As shown in these drawings, in this modified example, a frame 71 that supports the skirt 51 so as to be rotatable about a horizontal axis is provided, and both ends of the frame 71 are supported by the unit support mechanisms 5B1, 5B2, respectively. In this modified example, the first unit supporting mechanism 5B1, the second unit supporting mechanism 5B2, which are respectively located on the left and right sides in fig. 14, have different configurations.

In the first support mechanism 5B1, the piston rod 61A protrudes from the cylinder 60, and the piston rod 61A can move back and forth as in the above-described embodiment. The front end of the piston rod 61A is rotatably attached to the frame 71 via a bearing (not shown) with respect to the frame 71. Accordingly, the frame 71 is rotatable about the rotation center O3 in fig. 14 with respect to the piston rod 61A.

On the other hand, the rod end 64 of the second support mechanism 5B2 has a floating joint mechanism. Specifically, as shown in fig. 15, the rod supporting member 73 is supported on the frame 71 by the resin material 72, and the piston rod 61A is inserted through an opening formed at a central portion of the rod supporting member 73. Spherical stoppers 74 are mounted on the piston rod 61A on the upper and lower sides of the rod supporting member 73, respectively. Further, washers 75 are placed on the upper and lower surfaces of the lever support member 73, respectively, and a coil spring 76 is interposed between the lower washer 75 and the lower stopper 74. Accordingly, the piston rod 61A is movable relative to the frame 71 in a direction along the central axis of the piston rod 61A (up-down direction in fig. 15) with an elastic force within a predetermined range being applied, and is tiltable relative to the frame 71 as indicated by an arrow in fig. 15.

These unit support mechanisms 5B1, 5B2 support the automatic water mill unit 5 so as to be rotatable between a posture shown by a solid line in fig. 14 and a posture shown by an imaginary line in fig. 14, and the posture of the automatic water mill unit 5 can be changed within this rotation range by activating the air cylinder 60 to move the piston rod 61A back and forth in accordance with the shape of the coated surface of the vehicle body V.

Other embodiments

The present invention is not limited to the above-described embodiments and modified examples, and all modifications and applications covered by the scope and equivalent scope of the claims are possible.

For example, in the above-described embodiments and modified examples, the case where the present invention is applied to the automatic water mill apparatus 21 to the automatic water mill apparatus 24 having the vehicle body V as a painting object and performing automatic water milling on the painting surface of the vehicle body V has been described. The coated object in the present invention is not limited to the vehicle body V, and the present invention is applicable to an automatic water mill apparatus for various coated objects.

In the above-described embodiment and modified example, the abrasive paper 56 has the paper center hole 56c in the center portion, and water is pushed out toward the coated surface via the paper center hole 56 c. The present invention is not limited to this configuration, for example, when the entire abrasive paper 56 is made of a water absorbing material (such as sponge), the paper center hole is not absolutely necessary, and water pushed out from the pad center hole 55b of the cushion pad 55 flows to the coated surface through the abrasive paper 56. In this case as well, water is pushed out from the central portion of the polishing paper 56 toward the outer peripheral side between the polishing paper 56 and the coated surface, so that the automatic water-milling can be performed with a reduced possibility of clogging due to polishing dust.

In the above-described embodiment and modified example, the abrasive paper is used as the abrasive slide body, but an abrasive brush may be used instead.

In the above-described embodiment and modified example, the air motor 50 is used as the rotation power source, but an electric motor or the like may be used instead.

The present invention is applicable to an automatic water-milling apparatus that performs automatic water milling on a coated surface of a vehicle body.

Claims

1. An automatic water mill apparatus that performs automatic water milling in which a grinding slide body is pressed against a coated surface of a coated object that has been coated, and the grinding slide body moves as water flows between the grinding slide body and the coated surface to grind the coated surface, the automatic water mill apparatus comprising:

a housing forming an introduction space of the water;

a water supply pipe supplying the water to the introduction space;

a disk positioned closer to the painting surface than the lead-in space in a state in which the automatic water mill is performed;

a cushion pad integrally moved with the disk, and on which the grinding slider is mounted;

a disk center hole formed at a center portion of the disk;

A pad center hole formed at a center portion of the cushion pad and communicating with the disk center hole; and

a pushing-out device pushing out water that has been supplied to the introduction space through the water supply pipe toward the application surface via the disc center hole and the pad center hole,

wherein the push-out device has a stirring head which is arranged inside the housing and stirs the water in the introduction space, and

wherein the disk has a disk hole formed at a position relative to an outer peripheral side of the disk center hole and communicating with the introduction space, and a communication passage that communicates between the disk hole and the disk center hole to form a water passage in the disk from the disk hole through the communication passage to the disk center hole, the pad center hole communicating with the introduction space through the water passage.

2. The automatic water mill apparatus of claim 1, comprising a rotational power source for rotating the stirring head, wherein a center position of the stirring head is offset from a center of rotation of a drive shaft of the rotational power source.

3. The automatic water mill apparatus according to claim 2, wherein the position of the outer edge of the stirring head on the deviated side is on the inner peripheral side with respect to the outer peripheral end of the disk hole.

4. The automatic watermill apparatus of claim 1, wherein:

the disc is supported by the stirring head so as to be rotatable relative to the stirring head; and

a sealing member made of an elastic material is provided, one end edge of which is supported by the housing while the other end edge contacts a surface of the disk facing the introduction space, and which seals a gap between the housing and the disk.

5. The automatic water mill apparatus according to any one of claims 1 to 4, wherein an inner diameter of the disc center hole is set smaller than an inner diameter of the pad center hole.

6. The automatic water mill apparatus according to claim 2 or 3, wherein a center position of the disk is offset from the rotation center of the drive shaft of the rotary power source, and the offset is sized to be less than half an inner diameter of the disk center hole.